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 Statistical Learning


A definitive explanation to Hinge Loss for Support Vector Machines.

#artificialintelligence

NOTE: This article assumes that you are familiar with how an SVM operates. If this is not the case for you, be sure to check my out previous article which breaks down the SVM algorithm from first principles, and also includes a coded implementation of the algorithm from scratch! I have seen lots of articles and blog posts on the Hinge Loss and how it works. However, I find most of them to be quite vague and not giving a clear explanation of what exactly the function does and what it is. Instead, most of the time an unclear graph is shown and the reader is left bewildered.


Understanding Linear Regression

#artificialintelligence

Let's say you're looking to buy a new PC from an online store (and you're most interested in how much RAM it has) and you see on their first page some PCs with 4GB at $100, then some with 16 GB at $1000. So, you estimate in your head that given the prices you saw so far, a PC with 8 GB RAM should be around $400. This will fit your budget and decide to buy one such PC with 8 GB RAM. This kind of estimations can happen almost automatically in your head without knowing it's called linear regression and without explicitly computing a regression equation in your head (in our case: y 75x – 200). So, what is linear regression? Linear regression is just the process of estimating an unknown quantity based on some known ones (this is the regression part) with the condition that the unknown quantity can be obtained from the known ones by using only 2 operations: scalar multiplication and addition (this is the linear part).


An analysis of models on facial emotion detection

#artificialintelligence

Facial emotion detection is a common issue focused on in the field of cognitive science. An attempt to understand what exactly we as humans see in each other that gives us insight into other emotions is a challenge we can approach from an artificial intelligence side. While I don't have enough experience in psychology or even artificial intelligence to determine these factors, we can always start off by building a model to determine at least the start of this question. Fer2013 is a dataset with pictures of individuals labeled with the emotions of anger, happiness, surprise, disgust, and sadness. When testing humans on the dataset to correctly identify the facial expression of a set of pictures within the set, the accuracy is 65%.


Spectroscopy and Chemometrics News Weekly #47, 2020

#artificialintelligence

NIR Calibration-Model Services Spectroscopy and Chemometrics News Weekly 46, 2020 NIRS NIR Spectroscopy MachineLearning Spectrometer Spectrometric Analytical Chemistry foodindustry Analysis Lab Laboratories Laboratory Software IoT Sensors QA QC Testing Quality LINK Get the Spectroscopy and Chemometrics News Weekly in real time on Twitter @ CalibModel and follow us. Near-Infrared Spectroscopy (NIRS) "Near infrared absorption spectroscopy for the quantification of unsulfated alcohol in sodium lauryl ether sulfate" LINK "Estimation of Organic Carbon in Anthropogenic Soil by VIS-NIR Spectroscopy: Effect of Variable Selection" LINK "Near infrared spectroscopy (NIRS) based high-throughput online assay for key cell wall features that determine sugarcane bagasse digestibility") LINK "Authentication of barley-finished beef using visible and near infrared spectroscopy (Vis-NIRS) and different discrimination approaches" LINK "Energetic Distribution of States in Irradiated Low-Density ...


Learning The TensorFlow Way of Linear Regression

#artificialintelligence

We will loop through batches of data points and let TensorFlow update the slope and y-intercept. Instead of generated data, we will use the iris dataset that is built into the Scikit Learn. Specifically, we will find an optimal line through data points where the x-value is the petal width and the y-value is the sepal length. We choose these two because there appears to be a linear relationship between them, as we will see in the graphs at the end. We will also talk more about the effects of different loss functions in the next section, but for now we will use the L2 loss function.


Road Map for Choosing Between Statistical Modeling and Machine Learning

#artificialintelligence

When we raise money it's AI, when we hire it's machine learning, and when we do the work it's logistic regression. Machine learning (ML) may be distinguished from statistical models (SM) using any of three considerations: Uncertainty: SMs explicitly take uncertainty into account by specifying a probabilistic model for the data. Structural: SMs typically start by assuming additivity of predictor effects when specifying the model. Empirical: ML is more empirical including allowance for high-order interactions that are not pre-specified, whereas SMs have identified parameters of special interest. There is a growing number of hybrid methods combining characteristics of traditional SMs and ML, especially in the Bayesian world.


Structure Learning in Inverse Ising Problems Using $\ell_2$-Regularized Linear Estimator

arXiv.org Machine Learning

The inference performance of the pseudolikelihood method is discussed in the framework of the inverse Ising problem when the $\ell_2$-regularized (ridge) linear regression is adopted. This setup is introduced for theoretically investigating the situation where the data generation model is different from the inference one, namely the model mismatch situation. In the teacher-student scenario under the assumption that the teacher couplings are sparse, the analysis is conducted using the replica and cavity methods, with a special focus on whether the presence/absence of teacher couplings is correctly inferred or not. The result indicates that despite the model mismatch, one can perfectly identify the network structure using naive linear regression without regularization when the number of spins $N$ is smaller than the dataset size $M$, in the thermodynamic limit $N\to \infty$. Further, to access the underdetermined region $M < N$, we examine the effect of the $\ell_2$ regularization, and find that biases appear in all the coupling estimates, preventing the perfect identification of the network structure. We, however, find that the biases are shown to decay exponentially fast as the distance from the center spin chosen in the pseudolikelihood method grows. Based on this finding, we propose a two-stage estimator: In the first stage, the ridge regression is used and the estimates are pruned by a relatively small threshold; in the second stage the naive linear regression is conducted only on the remaining couplings, and the resultant estimates are again pruned by another relatively large threshold. This estimator with the appropriate regularization coefficient and thresholds is shown to achieve the perfect identification of the network structure even in $0


When Machine Learning Meets Privacy: A Survey and Outlook

arXiv.org Artificial Intelligence

The newly emerged machine learning (e.g. deep learning) methods have become a strong driving force to revolutionize a wide range of industries, such as smart healthcare, financial technology, and surveillance systems. Meanwhile, privacy has emerged as a big concern in this machine learning-based artificial intelligence era. It is important to note that the problem of privacy preservation in the context of machine learning is quite different from that in traditional data privacy protection, as machine learning can act as both friend and foe. Currently, the work on the preservation of privacy and machine learning (ML) is still in an infancy stage, as most existing solutions only focus on privacy problems during the machine learning process. Therefore, a comprehensive study on the privacy preservation problems and machine learning is required. This paper surveys the state of the art in privacy issues and solutions for machine learning. The survey covers three categories of interactions between privacy and machine learning: (i) private machine learning, (ii) machine learning aided privacy protection, and (iii) machine learning-based privacy attack and corresponding protection schemes. The current research progress in each category is reviewed and the key challenges are identified. Finally, based on our in-depth analysis of the area of privacy and machine learning, we point out future research directions in this field.


Improving Students Performance in Small-Scale Online Courses -- A Machine Learning-Based Intervention

arXiv.org Artificial Intelligence

The birth of massive open online courses (MOOCs) has had an undeniable effect on how teaching is being delivered. It seems that traditional in class teaching is becoming less popular with the young generation, the generation that wants to choose when, where and at what pace they are learning. As such, many universities are moving towards taking their courses, at least partially, online. However, online courses, although very appealing to the younger generation of learners, come at a cost. For example, the dropout rate of such courses is higher than that of more traditional ones, and the reduced in person interaction with the teachers results in less timely guidance and intervention from the educators. Machine learning (ML) based approaches have shown phenomenal successes in other domains. The existing stigma that applying ML based techniques requires a large amount of data seems to be a bottleneck when dealing with small scale courses with limited amounts of produced data. In this study, we show not only that the data collected from an online learning management system could be well utilized in order to predict students overall performance but also that it could be used to propose timely intervention strategies to boost the students performance level. The results of this study indicate that effective intervention strategies could be suggested as early as the middle of the course to change the course of students progress for the better. We also present an assistive pedagogical tool based on the outcome of this study, to assist in identifying challenging students and in suggesting early intervention strategies.


Gaussian Processes for Traffic Speed Prediction at Different Aggregation Levels

arXiv.org Artificial Intelligence

Dynamic behavior of traffic adversely affect the performance of the prediction models in intelligent transportation applications. This study applies Gaussian processes (GPs) to traffic speed prediction. Such predictions can be used by various transportation applications, such as real-time route guidance, ramp metering, congestion pricing and special events traffic management. One-step predictions with various aggregation levels (1 to 60-minute) are tested for performance of the generated models. Univariate and multivariate GPs are compared with several other linear, nonlinear time series, and Grey system models using loop and Inrix probe vehicle datasets from California, Portland, and Virginia freeways respectively. Based on the test data samples, results are promising that GP models are able to consistently outperform compared models with similar computational times.